Portable synchrotron, MIRRORCLE 20 in Ritsumeikan University is prepared as the infrared and far infrared synchrotron light source for the molecular dynamics study. The FTIR spectrometer and the dispersive‐type IR irradiation system using grating monochrometer are installed in the beam line. Sample cells with a temperature controller is prepared for the FTIR measurements of water‐rich samples like the aqueous solution, which encounters difficulty in a conventional FTIR system. The irradiation system provides monochromatic IR‐rays in the wave length between 2&mgr;m and 25&mgr;m. Dielectric relaxation spectroscopy (DRS) with network analyzer in the frequency range of 45MHz to 20GHz is prepared for the measurements of the sample irradiated by monochromatic IR‐rays. Research plans with the analysis system for dynamical water structure is described in this report. © 2004 American Institute of Physics